Amazon has the Cellucor C4 Original Pre Workout Powder (5.9oz, 30-Servings) in Watermelon for $18 - 25% off coupon (check "Save an extra" box, eligible on first S&S order for this product)  - 5% off with Subscribe & Save (can cancel at any time) = $13 with free shipping on $25+ or with Prime. Roughly 42 cents per serving.